Goniometer-based body-tracking device

Abstract

A sensing system is provided for measuring various joints of a human body for applications for performance animation, biomechanical studies and general motion capture. One sensing device of the system is a linkage-based sensing structure comprising rigid links interconnected by revolute joints, where each joint angle is measured by a resistive bend sensor or other convenient goniometer. Such a linkage-based sensing structure is typically used for measuring joints of the body, such as the shoulders, hips, neck, back and forearm, which have more than a single rotary degree of freedom of movement. In one embodiment of the linkage-based sensing structure, a single long resistive bend sensor measures the angle of more than one revolute joint. A second sensing device of the sensing system comprises a flat, flexible resistive bend sensor guided by a channel on an elastic garment.

What is claimed is:  
     
       1. An apparatus, comprising:
 a kinematic structure including a plurality of links, each link from the plurality of links being coupled to a remaining link from the plurality of links by a revolute joint from a plurality of revolute joints, the plurality of links including a first terminal link and a second terminal link;  
 a bend sensor configured to extend over the plurality of revolute joints, the bend sensor configured to send a position signal associated with a relative position of the first terminal link and the second terminal link; and  
 a mount coupled to the kinematic structure so that the kinematic structure is configured to move in relation to a body part.  
 
     
     
       2. The apparatus of  claim 1 , wherein the position signal is produced using forward kinematics. 
     
     
       3. The apparatus of  claim 1 , wherein the mount includes a garment having at least one pocket. 
     
     
       4. The apparatus of  claim 1 , wherein the mount includes a garment having at least one pocket configured to receive a mounting plate. 
     
     
       5. The apparatus of  claim 1 , wherein the mount includes a mounting plate configured to be attached to the body part. 
     
     
       6. The apparatus of  claim 1 , further comprising an actuator configured to output force feedback based on the position signal. 
     
     
       7. An apparatus, comprising:
 a garment having a first portion and a second portion, the first portion of the garment configured to at least partially cover a joint of a body, the second portion of the garment configured to at least partially cover a joint of the body different from the joint associated with the first portion of the garment;  
 a kinematic structure coupled to the garment, the kinematic structure configured to extend across the second portion of the garment, the kinematic structure including a plurality of links, each link from the plurality of links being coupled to a remaining link from the plurality of links by a revolute joint from a plurality of revolute joints, the kinematic structure including a first terminal link and a second terminal link, the plurality of links being moveable in at least one of a first degree of freedom and a second degree of freedom different from the first degree of freedom; and  
 a sensor coupled to the plurality of revolute joints, the sensor configured to output a signal associated with one of a relative movement and a relative position of the first terminal link and the second terminal link.  
 
     
     
       8. The apparatus of  claim 7 , further comprising an actuator configured to output force feedback based on the signal. 
     
     
       9. The apparatus of  claim 7 , wherein the sensor is a resistive bend sensor. 
     
     
       10. The apparatus of  claim 7 , wherein the kinematic structure is configured to extend across at least one of an elbow, a knee, a shoulder, a hip, an ankle, a wrist, and a portion of a spine. 
     
     
       11. The apparatus of  claim 7 , wherein the bend sensor is configured to measure an angle of a femur of a body relative to a torso of the body. 
     
     
       12. The apparatus of  claim 7 , wherein the bend sensor is configured to measure an angle of a humerus of a body relative to a torso of the body. 
     
     
       13. The apparatus of  claim 7 , wherein the position signal is associated with an angle between the first terminal link and the second terminal link. 
     
     
       14. An apparatus, comprising:
 a kinematic structure including a plurality of links, each link from the plurality of links being coupled to a remaining link from the plurality of links by a revolute joint, the plurality of links including a first terminal link and a second terminal link;  
 a sensor assembly including a plurality of bend sensors, each bend sensor from the plurality of bend sensors configured to overlap at least partially with a remaining bend sensor from the plurality of bend sensors, the sensor assembly configured to extend over each revolute joint and to send a signal associated with one of a relative movement between the first terminal link and the second terminal link and a relative position of the first terminal link and the second terminal link; and  
 a mount coupled to the kinematic structure so that the kinematic structure is configured to move in relation to a body part.  
 
     
     
       15. The apparatus of  claim 14 , wherein the mount includes a mounting plate configured to be attached to the body part. 
     
     
       16. The apparatus of  claim 14 , further comprising an actuator configured to output force feedback based on the signal. 
     
     
       17. The apparatus of  claim 14 , wherein the signal is associated with an angle between the first terminal link and the second terminal link.